<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>

<%
	pageContext.setAttribute("x",10);
	pageContext.setAttribute("y",20);
	
	pageContext.setAttribute("z",true);
	
%>

<h1>1. 运算</h1>
${x}<br />
${y}<br />
${x+y}<br />
${x*y}<br />

<h1>2. 判断</h1>
${x>y}

<h1>3. 逻辑运算</h1>
${(x>y)&&z}

<h1>4. 判断空</h1>
${empty z}<br />
${empty a}

</body>
</html>